Delayed onset enophthalmos and hypoglobus mimicking silent sinus syndrome following midface trauma.

Craniomaxillofacial trauma is primarily diagnosed and managed by oral and maxillofacial surgeons. Among the cases encountered, midface fractures involving orbital walls are highly prevalent. In these fractures, involvement of the orbital walls, particularly floor of the orbit, can lead to considerable aesthetic and functional limitations. From a maxillofacial perspective, indications for surgical repair of orbital floor encompass marked decrease in ocular motility, fracture affecting more than 50% of surface area, an increase in orbital volume exceeding 18% and enophthalmos greater than 2 mm. In the absence of these discernible signs, surgical intervention is not generally indicated. However, in this case, an early adolescent with a history of midface trauma and minimal orbital floor fracture 8 months earlier presented with progressively delayed onset enophthalmos and hypoglobus closely resembling features of silent sinus syndrome. The enophthalmos and hypoglobus were corrected by placing custom-made non-resorbable high-density polyethylene implant in the orbital floor. Postoperative follow-up demonstrated aesthetically and functionally satisfactory outcomes.

Clinical and radiographic assessment of patient-specific transantral reconstruction of orbital floor fractures: A case series.

To clinically and radiographically evaluate patient-specific titanium meshes via a trans-antral approach for correction of enophthalmos and orbital volume in patients with recent unilateral orbital floor fracture. Seven patients with unilateral orbital floor fractures received patient-specific titanium meshes that were designed based on a mirror-image of the contralateral intact orbit. The patient-specific implants (PSIs) were inserted via a trans-antral approach without endoscopic assistance. The patients were evaluated clinically for signs of diplopia and restricted gaze as well as radiographically for enophthalmos and orbital volume correction. Diplopia was totally resolved in two of the three patients who reported diplopia in the upward gaze. Whereas enophthalmos significantly improved in all but two patients, with a mean value of 0.2229 mm postoperatively compared to 0.9914 mm preoperatively. CT scans showed excellent adaptation of the PSIs to the orbital floor with a mean reduction of the orbital volume from 29.59 cc to 27.21 cc, a mean of 0.6% smaller than the intact orbit. It can be concluded that the proposed PSI can offer good reconstruction of the orbital floor through an isolated intraoral transantral approach with minimal complications. It could of special benefit in extensive orbital floor fractures.

Customized orbital implant versus 3D preformed titanium mesh for orbital fracture repair: A retrospective comparative analysis of orbital reconstruction accuracy.

This study aimed to compare the accuracy of inferomedial orbital fracture restoration using customized orbital implant versus 3D preformed titanium mesh. Patients were divided into two groups. Group 1 underwent surgery with customized orbital implants and intraoperative navigation, while group 2 was treated using 3D preformed titanium meshes with preoperative virtual surgical planning (VSP) and intraoperative navigation. Reconstruction accuracy was assessed by: (1) comparing the postoperative reconstruction mesh position with the preoperative VSP; and (2) measuring the difference between the reconstructed and unaffected orbital volume. Pre- and postoperative diplopia and enophthalmos were also evaluated. Fifty-two patients were enrolled (25 in group 1 vs 27 in group 2). The mean difference between final plate position and ideal digital plan was 0.62 mm (SD = 0.235) in group 1 and 0.69 mm (SD = 0.246) in group 2, with no statistical difference between the groups (p = 0.282). The mean volume differences between the reconstructed and unaffected orbits were 0.95 ml and 1.02 ml in group 1 and group 2, respectively, with no significant difference between the groups (p = 0.860). Overall clinical improvements, as well as complications, were similar. 3D preformed titanium meshes can reconstruct inferomedial fractures with the same accuracy as customized implants. Therefore, in clinical practice, it is recommended to use 3D preformed meshes for this type of fracture due to their excellent results and the potential for reducing time and costs.

Comparison of patient specific implant reconstruction vs conventional titanium mesh reconstruction of orbital fractures using a novel method.

To compare the reconstruction of orbital fractures using patient-specific implants (PSI) and conventional pre-formed titanium mesh; to develop a method of three-dimensional (3D) superimposition and analysis of the reconstructed orbits; and to present the pitfalls in 3D planning of orbital PSI and how to avoid them. This was a retrospective study of patients with orbital fractures who were treated in our institution between the years 2022 and 2023 using PSI or conservative prefabricated titanium mesh. Three different methods for virtual reconstruction of orbital fractures were used and are detailed with advantages, disadvantages and indications. Data acquired included age, gender, method of reconstruction, functional outcomes and aesthetic outcomes. 3D analysis for accuracy of reconstruction was performed. A total of 23 patients were included; 12 were treated using PSI and 11 using prefabricated titanium meshes. There were 8 male and 4 female patients in the PSI group comparted to 5 and 6 in the prefabricated group. All three virtual methods for reconstruction were used successfully, each with the proper indications. When comparing PSI reconstruction to conventional mesh, a significant difference in accuracy was observed; PSI cases showed an inaccuracy of 0.58 mm compared to 1.54 mm with the conventional method. Complications are presented, and tips for avoiding them are detailed. Three different methods for virtual reconstruction were used successfully; automated computerized reconstruction is used for small defects, repositioning is the superior method for non-comminuted cases while mirroring is the method of choice in comminuted fractures. 3D analysis can be performed using a novel method detailed in this report. PSI reconstruction showed superior results, indicating it should be the method of choice when possible. Pitfalls are presented and approaches to prevent them are discussed. Orbital reconstruction is a very important entity in maxillofacial surgery with crucial functional and esthetical implications, and one should use virtual planning and PSI implants, as they significantly improve outcomes.

Diagnostic pitfalls in pediatric orbital entrapment fractures.

Prompt diagnosis and management of orbital entrapment fractures in the pediatric patient have been advocated. This retrospective study analyzed a cohort of orbital entrapment fractures in pediatric patients with regard to diagnostic pitfalls, treatment and outcomes in a Level I trauma center in Germany. Based on medical records and radiological imaging, patients under the age of 18 years who presented with orbital fractures during 2009-2021 were analyzed. Overall, 125 patients presented with orbital fractures, of whom 29 patients (23.2%) had orbital entrapment fractures. The majority of patients presented with monocle hematoma (n = 23), diplopia (n = 20), and/or restricted extraocular eye movement (n = 14). While all patients with orbital entrapment fractures underwent three-dimensional imaging, 10 radiological reports (34.5%) did not include findings on orbital entrapment fractures. All patients underwent surgical exploration in less than 24 h. In 12 patients, clinical symptoms such as diplopia and restricted ocular elevation were documented upon postoperative evaluation before discharge. Considering the significant proportion of orbital entrapment fractures that are not noted on radiological imaging, prompt clinical examination should be initiated in pediatric patients at risk for orbital fractures. Urgent surgical intervention should be recommended in entrapment fractures.

Orbital Fractures: A New CT-Based Protocol to Guide the Surgical Approach and Reconstruction Material Decision-Making.

Preoperative computer-assisted planning and intraoperative navigation are becoming popular for orbital fracture treatment. However, not all institutions currently have access to these computer-aided applications. The authors present a simple and intuitive operative algorithm to guide orbital fracture reconstructions. The operative algorithm was based on linear measurements of orbital defects on high-resolution Computer tomography (CT) scans using specific axial, coronal, and sagittal plane images. The fractures were then divided into 3 types based on site and defect-size area. For each type, the authors suggested a surgical approach and material reconstruction. Between February 2022 and January 2023, 57 patients were treated according to the described CT-based protocol. The quality of reconstruction was classified as ideal, satisfactory, acceptable, and poor based on postoperative CT. Diplopia, enophthalmos, and postoperative complications were assessed. Fifty-seven patients were included. Forty-four (77.2%) patients were included in the type 1 group, 4 (7.01%) in the type 2 group, and 9 (15.79%) in the type 3 group. The reconstruction was considered ideal in 54 (94.7%) cases, satisfactory in 2 (3.5%), and acceptable in 1 (1.8%). No revision surgery was required. In all cases, preoperative diplopia was settled out, and only 1 patient reported postoperative enophthalmos. No complications occurred, with good clinical results and orbital symmetry. The linear CT measurement-based protocol is a simple and reliable workflow to guide the surgeon's choice of reconstruction material and surgical approach for primary orbital reconstruction. It allows good management of orbital trauma and could help standardize treatment decisions with an imaging technique available in all institutions.

Revisiting bilateral bony orbital volumes comparison using 3D reconstruction in Korean adults: a reference study for orbital wall reconstruction, 3D printing, and navigation by mirroring.

BACKGROUND: Orbital wall fractures can result in changes to the bony orbital volume and soft tissue. Restoring the bony orbital and intraconal fat volumes is crucial to prevent posttraumatic enophthalmos and hypoglobus. We aimed to establish an evidence-based medical reference point for "mirroring" in orbital wall reconstruction, which incorporates three-dimensional (3D)-printing and navigation-assisted surgery, by comparing bilateral bony orbital volumes. METHODS: We retrospectively analyzed the data obtained from 100 Korean adults who did not have orbital wall fractures, categorized by age groups. The AVIEW Research software (Coreline Soft Inc., Seoul, South Korea) was used to generate 3D reformations of the bony orbital cavity, and bony orbital volumes were automatically calculated after selecting the region of interest on consecutive computed tomography slices. RESULTS: The mean left and right orbital volume of males in their 20 s was 24.67 ± 2.58 mL and 24.70 ± 2.59 mL, respectively, with no significant difference in size (p = 0.98) and Pearson's correlation coefficient of 0.977 (p < 0.001). No significant differences were found in orbital volumes in other age groups without fractures or in patients with nasal bone fractures (p = 0.84, Pearson's correlation coefficient 0.970, p < 0.001). The interclass correlation coefficients (2,1) for inter- and intrarater reliability were 0.97 (p < 0.001) and 0.99 (p < 0.001), respectively. CONCLUSIONS: No significant differences were found in the bilateral bony orbital volumes among males of any age. Thus, the uninjured orbit can be used as a volumetric reference point for the contralateral injured orbit during orbital wall reconstruction.

Intraoperative Computed Tomography Use in Orbital Fracture Repair: A Systematic Review and Meta-Analysis.

Background: Intraoperative computed tomography (CT) allows surgeons to make adjustments during orbital fracture repair that may impact postoperative outcomes. Learning/Study Objectives: To determine the impact of intraoperative CT use on intraoperative revision and surgical outcomes for orbital fracture repair. Methods: A systematic review was performed in concordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines: the population was patients undergoing orbital fracture repair; intervention was use of intraoperative CT; comparison was patients not undergoing intraoperative CT; and outcomes were intraoperative revision rate, postoperative complications, and secondary revision surgeries. Meta-analysis was performed on the rate of intraoperative revision. Results: The search criteria yielded 790 articles, 377 were eligible for review, and 20 articles met criteria for analysis. In 19, intraoperative imaging led to immediate surgical corrections, with a random pooled effect size of 0.27 (0.20-0.35). Six studies reported secondary revision surgery rates (range 0-10.5%), and six studies reported postoperative complication rates (range 10-30%). Conclusions: Intraoperative imaging helps surgeons make precise, real-time adjustments in 27% of orbital fracture repair cases, which may improve surgical outcomes; however, more research is needed to investigate its impact on health care costs, operating time, and radiation exposure.

Automatic orbital segmentation using deep learning-based 2D U-net and accuracy evaluation: A retrospective study.

The purpose of this study was to verify whether the accuracy of automatic segmentation (AS) of computed tomography (CT) images of fractured orbits using deep learning (DL) is sufficient for clinical application. In the surgery of orbital fractures, many methods have been reported to create a 3D anatomical model for use as a reference. However, because the orbit bone is thin and complex, creating a segmentation model for 3D printing is complicated and time-consuming. Here, the training of DL was performed using U-Net as the DL model, and the AS output was validated with Dice coefficients and average symmetry surface distance (ASSD). In addition, the AS output was 3D printed and evaluated for accuracy by four surgeons, each with over 15 years of clinical experience. One hundred twenty-five CT images were prepared, and manual orbital segmentation was performed in all cases. Ten orbital fracture cases were randomly selected as validation data, and the remaining 115 were set as training data. AS was successful in all cases, with good accuracy: Dice, 0.860 ± 0.033 (mean ± SD); ASSD, 0.713 ± 0.212 mm. In evaluating AS accuracy, the expert surgeons generally considered that it could be used for surgical support without further modification. The orbital AS algorithm developed using DL in this study is extremely accurate and can create 3D models rapidly at low cost, potentially enabling safer and more accurate surgeries.

Predictors of Intraoperative Difficulty and Postoperative Examination Abnormalities in 164 Orbital Operations.

BACKGROUND: Although orbital fractures are common, prediction of outcomes in orbital surgery can be quite challenging. PURPOSE: We aim to identify predictors of intraoperative difficulty, operating time, and postoperative examination abnormalities in subjects undergoing post-traumatic orbital reconstructions. STUDY DESIGN, SETTING, AND SAMPLE: This is a retrospective cohort study of all consecutive orbital operations performed at a private, Level 1 trauma center in Portland, Oregon, USA over an 82-month period. All subjects that underwent exploration of the internal orbit for traumatic indications during the study period were included in the cohort. PREDICTOR VARIABLES: Four plating styles, surgical approach (transorbital vs transantral), days from injury to first surgery, fracture size (approximated as a rectangle using linear measurements from computed tomography scans), anteroposterior fracture position, and medial wall involvement were examined. OUTCOME VARIABLES: The primary outcome variable was intraoperative difficulty (defined as requiring revision after intraoperative imaging or return to the operating room). Secondary outcome variables included operating time and postoperative examination abnormalities. COVARIATES: Age and sex were included. ANALYSES: χ2 and Regression analyses were performed using a significance level of P < .05. RESULTS: One hundred and sixty four orbital operations were performed (90 isolated injuries and 74 combined orbital/midface injuries) on 155 subjects (73% male, mean age 39.8 years, standard deviation 16.7). In subjects with isolated orbital fractures, medial wall involvement was associated with intraoperative difficulty (P = .01). When using a transantral approach, intraoperative difficulty was more likely in more anterior fractures (P = .02). Plating style was associated with operating time (P = .03), with median times from 81 to 105 minutes (range 21 to 248 minutes). Postoperative examination abnormalities were more likely in the transorbital approach group (P = .01). Neither days to first surgery nor intraoperative difficulty were associated with postoperative examination abnormalities. Postoperative eyelid changes were seen in 13.6% of transorbital approaches and 0% of transantral approaches. Correction of gaze restriction and enophthalmos were more likely than correction of diplopia (P < .01). CONCLUSIONS AND RELEVANCE: Medial wall involvement is associated with intraoperative difficulty in orbital surgery. Anteriorly positioned fractures are better treated transorbitally, while posterior fractures may be amenable to transantral repair, thus avoiding risk of lower eyelid changes.

Reconstruction of Medial Orbital Wall Using Autologous Perpendicular Plate of Ethmoid.

The aim of this study is to investigate the feasibility of perpendicular plate of ethmoid as material for the reconstruction of medial orbital wall. The main outcome measurement was preoperative and postoperative orbital volume. The authors performed a study including 17 patients who have isolated medial orbital wall fracture (blow-out fracture). All the patients were fixed the defect using autologous perpendicular plate of ethmoid under endonasal approach. The authors compared the preoperative and postoperative orbital volume difference (unaffected orbit, affected orbit) of all the patients, and observed the improvement of diplopia or ocular motility disorders after operation. All 17 medial orbital wall reconstruction surgeries were successful with no severe postoperative ophthalmic complications. Statistically significant differences were found between the preoperative and postoperative orbital tissue volumes for the affected orbit. There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction. And postoperative computed tomography showed the implant is in place and there is no medial rectus incarceration. Autologous perpendicular plate of ethmoid proved to be safe and effective in the reconstruction of medial orbital wall under endonasal approach with cost-effectivence, low complication rate, high biocompatibility, and minimally invasion.

Long-Term Aesthetic Cicatrization Analysis of Lower Eyelid Incision for Orbital Floor Fracture Approach.

Orbital fractures are among the most frequent facial injuries. Of the 3 most widely described approaches in the literature, the lower eyelid approach is the authors' preference. This study retrospectively analyzed the patients treated at the Trauma Center of the Umberto I Hospital, Sapienza University of Rome from January 2010 to December 2020. Inclusion criteria were as follows: diagnosis of pure/impure orbital bone fracture, complete clinical and radiological documentation, and a minimum of 12 months follow-up. Sex, age, etiology, treatment, and associated complications were analyzed using IBM SPSS Statistics. Two internationally validated scales were used for the functional and esthetic long-term evaluation: the Patient and Observer Scar Assessment Scale (POSAS) and the Vancouver one. The scales were compiled by the patient himself and by 3 independent expert observers. Of the 543 patients who underwent surgery in the specified period, 208 fully met the inclusion criteria. One hundred forty-two (68.2%) were males and 66 (31.8%) were females, with a mean age of 40.68 years. The main cause was represented by assaults (33.1%). One hundred seventy-nine patients had a pure orbital fracture (83.8%) and 29 an impure one (16.2%). The most frequent symptoms at the time of diagnosis were diplopia (31.2%), followed by anesthesia of the second trigeminal branch (24.3%). Open reduction with internal fixation was the preferred treatment and proved to be effective in reducing the main signs and symptoms of the fracture in a statistically significant way ( P < 0.05). Long-term esthetic results of the lower eyelid, using the Vancouver and POSASs, were respectively as follows: Vancouver Scar Scale mean total score was 2.41 (range: 0-8), observer POSAS mean total score was 1.83 (range: 1.2-3.9), observer general opinion mean score was 1.66, patient POSAS mean total score was 2.23 (range: 1.33-3.7), and patient general opinion mean score was 2.87. The lower eyelid approach has proven to be reproducible, with a fast-learning curve and a low complication rate. The analysis conducted highlighted an excellent long-term esthetic-functional result. Further studies will be needed to statistically compare the results obtained with other orbital floor surgical approaches.

Orbital Reconstruction Using a Polyetheretherketone Patient-Specific Implant After Removal of a Mucocele Developing After Orbital Fracture Repair.

A few mucoceles developing secondary to facial bone fractures have been reported. Mucocele formation is thought to be attributable to displacement of the respiratory mucosa with obstruction of the sinus opening, especially if untreated. Accurate diagnosis and management are required; a growing mucocele will gradually destroy adjacent bony structures and cause irreversible complications. The authors describe a patient who presented with diplopia and mild discomfort when gazing upward. She had undergone reconstruction of medial and inferior orbital fractures 20 years previously. The patient was diagnosed with a mucocele developing after orbital fracture repair. The patient underwent mucocele removal and orbital reconstruction using a polyetheretherketone patient-specific implant. In a patient with orbital symptoms but without acute trauma, a mucocele should be among the differential diagnoses if history-taking reveals past orbital trauma and surgery. A polyetheretherketone patient-specific implant was effective for orbital reconstruction after mucocele removal.

Accuracy of Orbital Shape Reconstruction-Comparative Analysis of Errors in Implant Shape Versus Implant Positioning: A Cadaveric Study.

INTRODUCTION: Orbital blowout fractures are commonly reconstructed with implants shaped to repair orbital cavity defects, restore ocular position and projection, and correct diplopia. Orbital implant shaping has traditionally been performed manually by surgeons, with more recent use of computer-assisted design (CAD). Accuracy of implant placement is also key to reconstruction. This study compares the placement accuracy of orbital implants, testing the hypothesis that CAD-shaped implants indexed to patient anatomy will better restore orbit geometry compared with manually shaped implants and manually placed implants. METHODS: The placement accuracy of orbital implants was assessed within a cadaveric blowout fracture model (3 skulls, 6 orbits) via 3-dimensional CT analysis. Defects were repaired with 4 different techniques: manually placed-manually shaped composite (titanium-reinforced porous polyethylene), manually placed CAD composite, indexed placed CAD composite, and indexed placed CAD titanium mesh. RESULTS: Implant placement accuracy differed significantly with the implant preparation method ( P =0.01). Indexing significantly improved the placement accuracy ( P =0.002). Indexed placed titanium mesh CAD implants (1.42±0.33 mm) were positioned significantly closer to the intact surface versus manually placed-manually shaped composite implants (2.12±0.39 mm). DISCUSSION: Computer-assisted design implants indexed to patient geometry yielded average errors below the acceptable threshold (2 mm) for enophthalmos and diplopia. This study highlights the importance of adequately indexing CAD-designed implants to patient geometry to ensure accurate orbital reconstructions.

Pressure Onto the Orbital Walls and Orbital Morphology in Orbital Floor or Medial Wall Fracture: A 3-Dimensional Printer Study.

The purposes of this study were to compare the pressure onto the orbital floor and medial orbital wall between 3-dimensional printer skull models with unilateral orbital floor and medial orbital wall fractures and to compare the morphology of the orbital floor and medial orbital wall between patients with unilateral orbital floor and medial orbital wall fractures. The skull models were created based on computed tomographic (CT) data obtained from every 10 patients with unilateral orbital floor and medial orbital wall fractures. The orbital spaces of these models were filled with silicone, the silicone surface was pushed down, and pressures onto the orbital floor and the medial orbital wall were measured. On preoperative computed tomographic images taken in the same 20 patients, the superior and lateral bulges of the orbital floor and medial orbital wall were measured, respectively. The measurements were done on the unaffected sides. Consequently, the pressure onto the orbital floor was significantly higher in the orbital floor fracture models than in the medial orbital wall fracture models, although the pressure onto the medial orbital wall was not significantly different between the models. As for the morphologic study, the superior bulge of the orbital floor was higher in the orbital floor fracture group than in the medial orbital wall fracture group. The results of this study indicate that since the orbital floor with a high superior bulge receives high hydraulic pressure, patients with a high superior bulge have a greater risk of orbital floor fracture.

Orbitalization of Ethmoidal Sinus With Stacked Cross-linked Acellular Dermal Matrix: A New Strategy to Reconstruct Medial Orbital Wall Fracture.

BACKGROUND: The use of an acellular dermal matrix (ADM) has not been reported in medial orbital wall fracture reconstruction previously. This study aimed to share our early experience with the cross-linked ADM as an allograft material for medial orbital wall reconstruction. METHODS: In this study, the author evaluated the medical records and serial facial computed tomography scans of 27 patients with pure medial orbital wall fractures reconstructed by a single surgeon between May 2021 and March 2023. The author routinely approached the medial orbital wall with a retrocaruncular incision. Five out of 27 patients were reconstructed with trimmed, multiple folded, 1.0-mm-thick cross-linked ADM (MegaDerm; L&C Bio, South Korea). RESULTS: All cases reconstructed with cross-linked ADM improved clinically and radiologically without complications. The serial computed tomography findings revealed that implanted cross-linked ADM successfully covered the defect while providing a significant volumizing effect. CONCLUSIONS: This is the first study to show the efficacy of cross-linked ADM for orbital medial wall fracture reconstruction. Our strategy of orbitalization of ethmoidal sinus with stacked cross-linked ADM would be an excellent surgical option.

Changes in Facial Symmetry Following Computer-Assisted Secondary Correction of Craniofacial Fractures.

OBJECTIVE: For patients without dysfunctions, the main purpose of secondary correction for craniofacial fractures is restoring facial symmetry. Computer-assisted surgery techniques including virtual surgical planning and intraoperative navigation provide the help to restore the bony symmetry as much as possible. The authors retrospectively quantitatively analyzed patients who received computer-assisted secondary correction for craniofacial fractures on facial symmetry pre and postoperation. METHODS: This observational study reviewed the medical records of 17 patients requiring secondary correction for craniofacial fractures. Pre and postoperative computed tomography data were used to quantitatively analyze the changes in facial symmetry and enophthalmos. RESULT: All patients enrolled in this study showed mid-facial asymmetry but without dysfunctions except for enophthalmos, and 5 patients had bone defects in the frontal-temporal area. The corrective surgical techniques were different for each patient according to their specific condition. Virtual surgical planning with or without intraoperative navigation was performed for all patients. Compared with the preoperative condition, their facial symmetry was significantly improved. The maximum discrepancy value between the affected side and the mirrored unaffected side decreased from 8.10 ± 2.69 to 3.74 ± 2.02 mm postoperatively, and the mean discrepancy value decreased from 3.58 ± 1.29 to 1.57 ± 0.68 mm. In addition, the Enophthalmos Index decreased from 2.65 to 0.35 mm. CONCLUSION: This observational study objectively demonstrated that computer-assisted secondary correction for craniofacial fractures can significantly improve facial symmetry. And the authors recommend that virtual surgical planning and intraoperative navigation should be a must step in craniofacial fracture correction.

Are Magnetic Resonance Imaging-Generated 3Dimensional Models Comparable to Computed Tomography-Generated 3Dimensional Models for Orbital Fracture Reconstruction? An In-Vitro Volumetric Analysis.

BACKGROUND: Magnetic resonance imaging (MRI) is being increasingly considered as an alternative for the evaluation and reconstruction of orbital fractures. No previous research has compared the orbital volume of an MRI-imaged, three-dimensional (3D), reconstructed, and virtually restored bony orbit to the gold standard of computed tomography (CT). PURPOSE: To measure the orbital volumes generated from MRI-based 3D models of fractured bony orbits with virtually positioned prebent fan plates in situ and compare them to the volumes of CT-based virtually reconstructed orbital models. STUDY DESIGN: This retrospective in-vitro study used CT and MRI data from adult patients with orbital trauma assessed at the Royal Brisbane and Women's Hospital Outpatient Maxillofacial Clinic from 2011 to 2012. Only those with orbital blowout fractures were included in the study. PREDICTOR VARIABLE: The primary predictor variable was imaging modality, with CT- and MRI-based 3D models used for plate bending and placement. MAIN OUTCOME VARIABLE: The primary outcome variable was the orbital volume of the enclosed 3D models. COVARIATES: Additional data collected was age, sex, and side of fractured orbit. The effect of operator variability on plate contouring and orbital volume was quantified. ANALYSES: The Wilcoxon signed rank test was used to assess differences between orbital volumes with a significance level P < .05. RESULTS: Of 11 eligible participants, six patients (four male and two female; mean age 31 ± 8.6 years) were enrolled. Two sets of six CT-based virtually restored orbits were smaller than the intact contralateral CT models by an average of 1.02 cm3 (95% CI -0.07 to 2.11 cm3; P = .028) and 0.99 cm3 (95% CI 0.07 to 1.91 cm3; P = .028), respectively. The average volume difference between the MRI-based virtually restored orbit and the intact contralateral MRI model was 0.97 cm3 (95% CI -1.08 to 1.94 cm3; P = .75). Imaging modality did affect orbital volume difference for 1 set of CT and MRI models (0.63 cm3; 95% CI -0.11 to 1.29 cm3; P = .046) but not the other (0.69 cm3; 95% CI -0.11 to 1.23 cm3; P = .075). Single operator variability in plate bending did not result in significant (P = .75) volume differences. CONCLUSIONS: MRI can be used to reconstruct orbital volume with a clinically acceptable level of accuracy.

Individualized implants using point-of-care printed models in the treatment of orbital blowout fractures.

OBJECTIVE: This case series aims to highlight the digital workflow used by our institution to treat orbital fractures by creating individualized implants using point-of-care, 3-dimensional (3D) printed models. STUDY DESIGN: The study population comprised consecutive patients who presented to John Peter Smith Hospital with isolated orbital floor and/or medial wall fractures from October 2020 to December 2020. Patients treated within 14 days of their initial injury and with 3 months postoperative follow-up were included. Bilateral orbit fractures were excluded because an intact contralateral orbit is needed for 3D modeling. RESULTS: A total of 7 consecutive patients were included. The orbital floor was involved in 6 of the fractures, whereas 1 fracture involved the medial wall. All patients with preoperative diplopia, enophthalmos, or both had resolution by the 3-month postoperative follow-up appointment. Postoperatively, there were no complications in all patients included. CONCLUSIONS: The point-of-care digital workflow presented allows for the efficient production of individualized orbital implants. This method may produce a midface model in hours that can be used to pre-mold an orbital implant to the mirrored, unaffected orbit.

A Preoperative Imaging Evaluation to Avoid Orbital Complications in Functional Endoscopic Sinus Surgery.

Functional endoscopic sinus surgery has become popular worldwide. However, serious complications have been reported with it. A preoperative imaging evaluation is thus essential to avoid complications. The authors compared 0.5 mm slice computed tomography (CT) images reconstructed from sinus CT data with conventional 2 mm slice CT images. The authors evaluated patients who underwent endoscopic surgery. Data regarding age, sex, history of craniofacial trauma, diagnosis, operative procedure, and CT findings of eligible patients were extracted from medical records and retrospectively reviewed. One hundred twelve patients underwent endoscopic surgery during the study period. Six patients (5.4%) had orbital blowout fractures, and half of them could only be identified by 0.5 mm slice CT images. The authors presented the usefulness of 0.5 mm slice CT images in the preoperative imaging evaluation of functional endoscopic sinus surgery. Surgeons should also recognize that a small number of patients have "stealth" (asymptomatic and unrecognized) blowout fractures.